MISHIMOTO Subaru WRX / STI Coolant Overflow Tank, Polished 2008-2021

The Mishimoto Coolant Overflow Tank for the 2008+ Subaru WRX and WRX STI replaces the factory plastic reservoir with a durable, TIG‑welded aluminum unit engineered for long‑term reliability. OEM plastic tanks are susceptible to cracking, discoloration, and structural fatigue caused by repeated thermal cycling, and their appearance detracts from the engine bay. Mishimoto’s aluminum construction eliminates these concerns, providing improved resilience and a refined, motorsport‑inspired aesthetic.

A CNC‑machined dipstick is integrated for quick and accurate coolant‑level inspection, and the tank is designed to fit cleanly with both stock and Mishimoto WRX/STI radiators. Available in polished or anodized‑black finishes, the tank complements a wide range of engine‑bay styles while delivering a functional upgrade over the factory component. As with all Mishimoto WRX/STI products, the Coolant Overflow Tank is backed by the Mishimoto Lifetime Warranty.